Types of Diamonds and How to Tell Real from Fake
Part 1: Types of Diamonds
Diamonds are mainly categorized into two groups:
1. Natural Diamonds:
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White (Colorless) Diamonds: The most valuable type; the more colorless, the higher the value.
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Fancy Color Diamonds: Diamonds with natural colors due to impurities or crystal defects:
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Yellow and Brown: The most common fancy colors.
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Blue: Due to the presence of boron.
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Pink/Red: Rare and extremely expensive.
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Green: Caused by exposure to natural radiation.
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Rough Diamonds: Untouched diamonds in their original crystal form.
2. Synthetic (Man-Made) Diamonds:
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Lab-Grown Diamonds: Chemically and physically identical to natural diamonds but created in a lab in a much shorter time. They are significantly less expensive.
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Diamond Imitations: Stones like Cubic Zirconia (CZ) and Moissanite that only look similar to diamonds but have completely different chemical compositions.
Part 2: How to Tell Real from Fake
1. The Fog Test (Simple but Not Conclusive):
A real diamond disperses heat instantly. Breathe on the stone. If the fog dissipates immediately, it's likely real. If it stays for a few seconds, it's probably fake. (Moissanite also passes this test).
2. The Read-Through Test (For Cut Diamonds):
A diamond refracts light intensely. Place the stone table-down over text or a line. If you cannot read the text clearly through the stone, or see heavily distorted lines, it's likely real. If the text is easily readable, it's fake (usually CZ).
3. Weight Check (Comparative):
Diamond is lighter than many simulants of the same size. A cubic zirconia of the same size as a diamond will weigh significantly more.
4. Using a Loupe (Jeweler's Magnifier):
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Natural Inclusions: Natural diamonds often have small internal imperfections (carbon spots, tiny crystals). Lab-grown diamonds are often much cleaner or have metallic inclusions. Cubic Zirconia is usually flawless.
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Edges: The edges of a real diamond are sharp and precise due to its extreme hardness. The edges of softer stones like CZ often appear worn and rounded.
5. Density Test (Specialized):
Diamond has a specific gravity of about 3.52 g/cm³. Density can be calculated by measuring weight in air and water. This method is useful for distinguishing diamond from CZ (SG ~5.7).
6. Electrical Conductivity Test (To distinguish from Moissanite):
Moissanite (like diamond) has thermal conductivity, but unlike diamond, it is also an electrical conductor. Diamond testers use this property to easily tell moissanite apart from diamond.
The Most Important and Reliable Method:
Obtaining a Certificate from a reputable gemological laboratory like GIA, IGI, or HRD. These certificates verify the identity, quality (4Cs), and whether the diamond is natural or lab-grown.Conclusion:
While simple initial tests exist, the only way to be 100% sure is to consult a professional gemologist and get a certificate from an accredited lab. For investment or significant purchases, this step is essential.